Cloud vs. on-premises: Finding the right balance

Sandra Gittlen |
May 2, 2017

The process of figuring out which apps work in the cloud vs. on-premises doesn't yield the same results for everyone.

Supporting that communication network and the data it generates will require more than the internal data center, though. Schachter says the effort will draw on a hybrid of on-premises and cloud-based applications and infrastructure. He expects to tap a combination of platform as a service, infrastructure as a service, and SaaS to get to the best of breed for each element of the program.

"We can use the scale of cloud providers and their expertise to do things we wouldn't be able to do internally," he says, adding that all providers must meet NYC DOT's expectations of "safer, faster, smarter and cheaper."

Apps saved for on-premises

In fact, Schachter has walled off only a few areas that aren't candidates for the cloud -- such as emergency services and email. "NYC DOT is one of the most sued entities in New York City, and we constantly need to search our corpus of emails. We have a shown a net positive by keeping that application on-premises to satisfy Freedom of Information Law requests as well as litigation," he says.

The City of Los Angeles also has its share of applications that are too critical to go into the cloud, according to Ted Ross, CIO and general manager of the city's Information Technology Agency. For instance, supervisory control and data acquisition (SCADA), 911 Dispatch, undercover police operations, traffic control and wastewater management are the types of data sets that will remain on-premises for the foreseeable future.

"The impact of an abuse is so high that we wouldn't consider these applications in our first round of cloud migrations. As you can imagine, it's critical that a hacker not gain access to release sewage into the ocean water or try to turn all streetlights green at the same time," he says.

The cloud does serve as an emergency backup to the $108 million state-of-the-art emergency operations center. "If anything happens to the physical facility, our software, mapping and other capabilities can quickly spin up in the cloud," he says, adding that Amazon Web Services and Microsoft Azure provide many compelling use cases.

The city, with more than 1,000 virtual servers on-premises, considers the cloud a cost-effective godsend. "We very much embrace the cloud because it provides an opportunity to lower costs, makes us more flexible and agile, offers off-site disaster recovery, empowers IT personnel, and provides a better user experience," he says.

As an early adopter of Google's Gmail in 2010, Ross appreciates the value of the cloud, so much so that in 2014, the city made cloud a primary business model, starting with SaaS, which he calls "a gateway drug to other cloud services."

Eventually, the city ventured into infrastructure as a service, including using "a lot of Amazon Web Services," which Ross describes as more invasive than SaaS and more in need of collaboration between the service provider and the network team. "You have to be prepared to have a shared security model and to take the necessary steps to enact it," he says. Cloud computing also requires additional network bandwidth to reduce latency and maximize performance, he adds.